Conventional cellular networks, including conventional LTE networks, employ frequent user equipment (UE) handovers, particularly in heterogeneous-network deployment scenarios including macrocells and smallcells (i.e., picocells, femtocells, remote radio heads (RRH), and other smallcell types). For example, because a smallcell coverage region may encompass a smaller region than that of a macrocell, a UE wirelessly connected only to the smallcell may need to handover to a macrocell or to a second smallcell as the UE is moved from the initial smallcell coverage region. On the other hand, handover may not be necessary when the UE is already connected to the macrocell and is within its larger coverage region, but offloading data transmission bandwidth served by a smallcell would not be available if the UE is connected to only the macrocell.
Previous attempts to achieve offloading and to reduce the frequency of handovers have employed carrier aggregation (CA). In CA systems, a UE is simultaneously served by at least two serving cells: a primary cell (PCell) and one or more secondary cell(s) (SCell). For example, a macrocell may serve as a PCell that provides non-access stratum (NAS) mobility information and security input whereas a smallcell may serve as an SCell downlink secondary component carrier providing additional data transmission bandwidth that the UE offloads to the smallcell. Because the PCell is responsible for the network connection mobility management of the UE, the UE need not handover so long as the UE is moving within the macrocell coverage region.